Sometimes You Have To Whack It !!

[Nimravis]

Yesterday, while I was at the Chicago Gem and Mineral Show, I bought a bucket of Mazon Creek concretions for $30. Now the last thing I needed was more concretions to open, but I wanted to buy something from the seller, who was a longtime MC collector. After getting home I decided to whack a bunch of them open and did the same today from that bucket as well as some others. Now I would have opened more yesterday, but had to stop after I whacked my thumb open. It is never fun when a concretion move and you hit your thumb.

 

I did not find anything worth keeping, hopefully I will have time tomorrow to open more concretions.

 

As usual, a lot of the concretions split nicely and nothing was inside- see below.

 

 

 

 

 

Several had plant material inside.

 

 

 

 

 

 

I found a poorly preserved worm.

 

 

A couple poorly preserved clams.

 

 

2 pieces of coprolite?

 

 

 

A poorly preserved fern.

 

 

I think that this was one of my poorest showings since I started this thread. I believe I went through about 150 concretions in the two days.

 

Hopefully I will have better luck tomorrow.

[stats]

Sorry about that!  Good thing you didn't freeze thaw and have to wait 10 years to find out!  Perfectly shaped concretions that end up being blanks are one of the saddest things!

 

Cheers,

Rich

[Nimravis]

49 minutes ago, stats said:

Sorry about that!  Good thing you didn't freeze thaw and have to wait 10 years to find out!  Perfectly shaped concretions that end up being blanks are one of the saddest things!

 

Cheers,

Rich

I agree and if I had to move them to a different state when I move would be a pain.

[Yoda]

8 hours ago, Nimravis said:

 

 

I think that this was one of my poorest showings since I started this thread. I believe I went through about 150 concretions in the two days.

 

Hopefully I will have better luck tomorrow.

What a shame  

But at least you helped the seller out. 

 

Hopefully you will find something decent in the next batch that you open 

[Wrangellian]

Ow!  Talk about adding insult to injury... Bang your thumb and get a poor catch in return. Oh well, we all have our bad days.

Are you moving to a different state?

[Nimravis]

33 minutes ago, Wrangellian said:

Ow!  Talk about adding insult to injury... Bang your thumb and get a poor catch in return. Oh well, we all have our bad days.

Are you moving to a different state?

I plan on retiring in about a year and the wife wants to get out of Illinois and we are most likely moving to Georgia.

[Wrangellian]

Ah. A whole different fossil milieu to explore.

[Tidgy's Dad]

I quite like the worm, but otherwise I'd be pretty disappointed. 

Sorry about your thumb. 

[Nimravis]

After spending several hours out in the 88 degree heat helping a neighbor lay down pavers blocks for a bbq patio, I decided to whack open a few more concretions.

 

I put together these two piles and went at it. Many of them were the shapes that you want to find, some were large, others were small.

 

 

 

As usual, many broke open beautifully, but were duds-

 

 

 

 

 

 

As with yesterday, I found several pieces that had plant material, most likely subsurface bark.

 

 

 

 

This piece I also believes has coprolite on it.

 

 

 

Here is a nice little piece, most likely Pecopteris.

 

 

This next piece is a very badly preserved partial Neuropteris.

 

 

This next piece looks like a partial Cyclopteris.

 

 

 

I found several Myalinella meeki clams, the first piece has what was in the past called Spirobus worms, that is not the correct name, but I cannot think of it right now. The clam is coming out of the top of the concretion.

 

 

Here are other pieces-

 

 

 

 

 

 

CONTINUED ON NEXT POST-

 

 

 

 

[Nimravis]

 

 

 

 

This next piece contains crush clam shells-

 

 

 

Lastly, here is a piece of coprolite.

 

 

[Tidgy's Dad]

Thanks for keeping us up to date.

Microconchids is the name you're looking for, I think. 

[stats]

Spirobus is now a synonym?  I hadn't heard that.   That last one could also be a sea cucumber or a leech.  I don't see a mouth for the sea cucumber or any fecal pellets for a leech.

 

I always enjoy this post... has to be one of the longest running.

 

I see you have a new cm piece. 

 

Cheers,

Rich

 

[Nimravis]

35 minutes ago, stats said:

I see you have a new cm piece.

Thanks- that was a gift from @Misha.

[Nimravis]

35 minutes ago, stats said:

That last one could also be a sea cucumber or a leech.

I was thinking that too, but I opted for poop, lol.

[Nimravis]

57 minutes ago, Tidgy's Dad said:

Microconchids is the name you're looking for

That’s the ticket Adam, thanks.

[Tidgy's Dad]

1 hour ago, stats said:

Spirobus is now a synonym?  I hadn't heard that.   That last one could also be a sea cucumber or a leech.  I don't see a mouth for the sea cucumber or any fecal pellets for a leech.

 

I always enjoy this post... has to be one of the longest running.

 

I see you have a new cm piece. 

 

Cheers,

Rich

 

Sprirorbus is a synonym of Spirorbis. It is a polychaete annelid that doesn't appear until the Miocene, though the related Serpula dates back as far as the Cretaceous. 

Any Jurassic or earlier forms are now known to be of the order Microconchida which seems to lie within the class Tentaculita. 

[Nimravis]

23 minutes ago, Tidgy's Dad said:

Sprirorbus is a synonym of Spirorbis. It is a polychaete annelid that doesn't appear until the Miocene, though the related Serpula dates back as far as the Cretaceous. 

Any Jurassic or earlier forms are now known to be of the order Microconchida which seems to lie within the class Tentaculita. 

In the book, “Richardson’s Guide to The Fossil Fauna of Mazon Creek”, referred to them as “Fossil tubes of Spirobis sp., that is how I always referred to them until I was advised that they were microconchids.

[Tidgy's Dad]

1 hour ago, Nimravis said:

In the book, “Richardson’s Guide to The Fossil Fauna of Mazon Creek”, referred to them as “Fossil tubes of Spirobis sp., that is how I always referred to them until I was advised that they were microconchids.

Yeah, when I studied geology at school and university they were still always referred to as Spirorbis. Some of my collection is still labelled as this and Serpula. Haven't got round to altering them all yet. I think it's a fairly recent change. 

[Mark Kmiecik]

1 hour ago, Nimravis said:

I was thinking that too, but I opted for poop, lol.

 

I'm leaning towards Achistrum segment. And the crushed shells seem to have some pectens in there also. You got a few nice pieces from this batch.

 

 

 

 

Edited May 31, 2022 by Mark Kmiecik
added info

[Nimravis]

This evening I whacked open about 50 concretions from the area that I call (Across from Pit 4). Though I did not find anything spectacular, I still like a couple of the pieces that I found.

 

I found a number of Myalinella meeki bivalves. 

 

 

 

 

 

 

 

This next concretion is larger, and thinner. When opening concretions like this one with a hammer is better to lightly tap it to see if it will break along the plane line, like this one did.

 

 

The above piece appears to contain pieces of Myalinella meeki bivalves. I have found concretions like this in the past and believe that they may be the coprolite of an animal that consumed them.

 

 

 

 

 

This next piece is similar to the above concretion. If my memory serves me correctly, I have only found concretions like this from this site.

 

 

 

I also found a few pieces with plant material.

 

 

 

 

 

This next piece reminds me of Calamities, but I think it might possibly be the subsurface of the non vascular plant Taeniophyllum latifolium.

 

 

 

Here are a couple miscellaneous ferns, nothing too well preserved.

 

 

 

 

 

 

 

Lastly, there are times when you come across concretions as small as the one below. Many times the hold nice little fossils, this one did not.

 

 

 

Edited June 4, 2022 by Nimravis

[Pagurus]

Thanks for posting your finds. I especially like those bivalves. The Myalinella meeki remind me of the tasty blue mussels, Mytilus edulus I find on the rocky beaches around here.

[Nimravis]

1 hour ago, Pagurus said:

Thanks for posting your finds. I especially like those bivalves. The Myalinella meeki remind me of the tasty blue mussels, Mytilus edulus I find on the rocky beaches around here.

They are very nice looking and don’t mind having those come out of the concretions.

[Mark Kmiecik]

14 hours ago, Nimravis said:

 

There may be something inside that. I have some half that size that originally split in this manner, most from across the street. I recommend two or three freeze/thaw cycles before tapping with a hammer as this type is on the "soft" side and crumbly compared to others. That site seems to yield a lot of clams.

Edited June 4, 2022 by Mark Kmiecik

[Nimravis]

5 hours ago, Mark Kmiecik said:

 

There may be something inside that. I have some half that size that originally split in this manner, most from across the street. I recommend two or three freeze/thaw cycles before tapping with a hammer as this type is on the "soft" side and crumbly compared to others. That site seems to yield a lot of clams.

These are not soft, this piece split open perfectly, there was just nothing inside.

[stats]

7 hours ago, Mark Kmiecik said:

 

There may be something inside that. I have some half that size that originally split in this manner, most from across the street. I recommend two or three freeze/thaw cycles before tapping with a hammer as this type is on the "soft" side and crumbly compared to others. That site seems to yield a lot of clams.

You read my mind, Mark!

 

Cheers,

Rich